超声造影评估闭合性肝损伤伴活动性出血的实验研究

目的探讨超声造影评估闭合性肝损伤伴活动性出血的价值。方法采用自制小型撞击器对10只实验猪肝区进行撞击，建立闭合性肝损伤伴活动性出血模型。采用二维超声及超声造影技术分别于撞击前、撞击后实时观察肝局部回声的变化情况。实验结束后处死实验动物取出肝，对损伤情况进行大体评估、常规HE染色检查，将二维声像图及超声造影检查结果与病理检查结果进行对比研究。结果二维声像图显示：10只实验猪肝局部损伤区均有回声强弱不等的点状、片状低回声或无回声区，与正常肝组织界限不清晰；7只可见肝包膜连续性中断，3只中断不明显；肝包膜外（膈下）均可见不同程度的积液。超声造影显示：动脉相及门脉相血管显像呈放射状增强的特征在损伤区中断，可显示微气泡回声自损伤（或裂口）处向外移动呈“涌泉状”或“喷射状”流人积液区，损伤区肝组织较正常肝组织增强延迟；延迟相正常肝组织增强回声开始减弱而损伤区回声减弱缓慢，损伤区因造影反差形成明显的边界。大体观察10只实验猪局部肝实质均发生不同程度的急性挫裂性损伤及肝包膜破裂，病理检查结果与超声造影结果基本一致。结论超声造影可实时、动态观察闭合性肝损伤的范围、程度及活动性出血的情况，对进一步临床治疗具有重要的价值。

Contrast-enhanced ultrasonography for evaluation of blunt hepatic trauma with active bleeding

Objective To evaluate contrast-enhanced ultrasonography in diagnosis of blunt hepatic trauma with active bleeding.Methods Self-made miniature impactor was used to make models of blunt hepatic trauma in ten pigs.Conventional two-dimensional ultrasonography and contrast-enhanced ultrasonography were used to detect local echo changes of the livers before and instantly after impacting.After experiments the livers were taken out for pathologic examination.Hematoxylin and eosin staining were performed on injuried regions.Results The sonographic pattern of lesions in the pigs' livers at conventional ultrasonography was hypo-echoic in various degrees or anechoic against normal parenchyma with poorly-defined margins.The ruptures of liver capsules were observed in 7 pigs,whereas the capsule ruptures were not showed in the other 3 pigs.The different degrees of blood accumulation were found under the diaphragm in ten pigs.The radiate enhancement of vessels was interrupted in the lesion areas in arterial phase and portal phase was demonstrated with contrast-enhanced ultrasonography.The microbubbles flowed from the ruptures to the areas of blood accumulation.The enhancement of lesion area was more delayed than that of healthy parenchyma.During the delayed phase the enhanced echogenicity of the normal parenchyma began to weaken,whereas the echogenicity of lesions weakened slowly.The injuried areas were against to normal parenchyma with clear borders due to contrast agent.Gross pathologic findings demonstrated that acute blunt hepatic traumas and liver captures happened in 10 pigs.Gross pathologic findings were consistent with the contrast-enhanced ultrasonographic results.Conclusions Contrast-enhanced ultrasonography can observe blunt hepatic trauma with active bleeding in real time,which is valuable to further clinical treatment.