犬缺血再灌注心肌靶向超声造影图像的组织定征量化研究

Ultrasound tissue characterization quantitative evaluation on myocardial injury using targeted contrast echocardiography

目的用超声组织定征量化分析白细胞靶向超声造影剂对犬心肌缺血再灌注（ischemiareperfusion，I-R）损伤声像图。方法将自制超声微泡造影剂“表活显”（self-made surfactant fluorocarbonfilled microbubbles，SFCMB）与磷脂酰丝氨酸（phosphatidylserine，PS）结合，制备成白细胞靶向超声微泡造影剂（SFCMB-PS），在实时心脏超声造影条件下，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Hi损伤处取组织块立即进行髓过氧化物酶（myeloperoxidase，MPO）活性测定。超声组织定征定量分析缺血再灌注损伤心肌。结果Hi损伤心肌声像图的回声强度[（22．56±4．62）GS]明显增高，与正常心肌[（16．57±3．82）GS]和缺血心肌[（5．00±2．58）GS]比较，差异均有统计学意义（P〈0．01），而且其与MPO活性有良好的相关关系（r=0．776，P〈0．05）。结论超声组织定征定量分析缺血再灌注心肌靶向超声显像能够较准确、客观地反映再灌注损伤的严重程度。

Objective To quantitatively analyse the imaging of myocardial ischemia-reperfusion（I-R） injury using leukocyte-targeted contrast echocardiography with ultrasound tissue characterization. Methods The phosphatidylserine（PS） was incorporated 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 I-R 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. Myocardial I-R injury was quantitive analysed by ultrasound tissue characterization. Results The gray scale of I-R myocardial [（22.56 ± 4.62）GS3 was increased than that of normal[（ 16.57 ±3.82）GS] and ischemic[（5.00± 2.58） GS] myocardial（ P 〈0.01）. And there was an good correlation（ r = 0. 776, P 〈0.05） between the gray scale of I-R myocardial and MPO activity. Conclusions It might accurately and objectly evaluate the myocardial I-R severity with quantitatively analyzing the targeted imaging using ultrasound tissue characterization.